Bug FAQAspen Twoleaf Tier Moth
Enargia decolor · Order: Lepidoptera · Family: Noctuidae
Also called: Pale Enargia Moth, Pale Enargia
Source: Wikipedia
The Aspen Twoleaf Tier Moth (Enargia decolor) is a noctuid moth with a wingspan of about 30 to 40 mm. Its larvae feed on several poplars, birch and alder and can cause extensive defoliation of trembling aspen forests. Adults fly from late July through early September, most commonly after mid-August.
Source: Wikipedia
How to recognize it
It belongs to the moth family Noctuidae.
Source: Wikipedia
Size
The wingspan ranges from 30 to 40 mm.
Source: Wikipedia
Where it lives
It lives across the Canadian boreal plain and at higher elevations in the western cordillera, where it depends on trembling aspen and other poplars.
Source: Wikipedia
What it eats
Larvae have been found on paper birch, balsam poplar, willows, bigtooth aspen, and speckled alder, and they can reach numbers high enough to heavily defoliate trembling aspen stands.
Source: Wikipedia
When you see it
The flight period for adults runs from late July through early September, peaking after mid-August.
Source: Wikipedia
Where it comes from
Its distribution is boreal-transcontinental, spanning the Canadian boreal plain and extending southward through western mountain ranges.
Source: Wikipedia
Lookalikes
Populations west of the Rockies down to New Mexico and Arizona may actually be a different species.
Source: Wikipedia
Where it is found in the US
Recorded in 26 of 51 states and DC. Most records: Minnesota, Montana, Michigan, New Hampshire, Wisconsin, Colorado, Vermont, New York.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What trees do the larvae feed on?
They eat paper birch, balsam poplar, willows, bigtooth aspen and speckled alder, and can heavily defoliate trembling aspen.
Source: Wikipedia
When are the adult moths active?
Adults fly from late July to early September, most often after mid-August.
Source: Wikipedia
Where is the Aspen Twoleaf Tier Moth found?
It occurs across the Canadian boreal plain and at higher elevations in the western cordillera, extending southward in the mountains.
Source: Wikipedia
Same family (Noctuidae)
Ipsilon Dart MothAgrotis ipsilonDamages trees, gardens or crops
Fall Armyworm MothSpodoptera frugiperdaDamages trees, gardens or crops
Army Cutworm MothEuxoa auxiliarisDamages trees, gardens or crops
Large Yellow UnderwingNoctua pronubaDamages trees, gardens or crops
Silver ΥAutographa gamma
American DaggerAcronicta americanaCan irritate skinSources
- Wikipedia: https://en.wikipedia.org/wiki/Enargia_decolor
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-24.